Former Russian tycoon Mikhail Khodorkovsky has accused the head of state oil giant Rosneft, Igor Sechin, of being behind a case in which one of Russia's richest men has been placed under house arrest.

Khodorkovsky told the daily "Vedomosti" that he believes Sechin, a powerful ally of President Vladimir Putin, wants to avert the threat of a decline in oil production by taking control of Bashneft, an oil company at the center of the case against AFK Sistema chairman Vladimir Yevtushenkov.

Khodorkovsky said "this is the very same Igor Ivanovich [Sechin], who has gotten no smarter in 11 years and may have gotten even greedier."

Khodorkovsky has accused Sechin of engineering his 2003 arrest and the downfall of his company, Yukos, whose main assets ended up in Rosneft's hands and helped it become Russia's biggest oil producer.

Khodorkovsky, who spent more than a decade in jail before Putin pardoned him last December and lives in Switzerland, said he does not believe Putin gave permission to target Yevtushenkov but that "he just doesn't see what is going on in front of his nose."

Vladimir Yevtushenkov

He said the case marked "the complete loss of control on the part of the president."

Alexander Shokhin, the head of the Russian Union of Industrialists and Enterpreneurs, earlier said that Yevtushenkov's arrest "undoubtedly looks like Yukos No. 2."

News of the case against Yevtushenkov chilled the Russian stock market, adding to concerns about the Russian economy in the wake of several rounds of Western sanctions over the crisis in Ukraine.

Russia's Micex Index had fallen 2 percent by late morning on September 17, dragged down by a 30 percent crash in shares in AFK Sistema.

Mikhail Khodorkovsky

Putin's spokesman, Dmitry Peskov, said any attempts to compare Yevtushenkov's arrest with the Yukos case were "unfounded and inappropriate."

He said the Kremlin understood markets could react "emotionally" but that this would not hinder the investigation.

The federal Investigative Committee said on September 16 that Yevtushenkov is suspected of taking part in a money-laundering scheme when AFK Sistema acquired shares in Bashneft.

He was ordered to remain under house arrest until November 16, but his lawyers had three days to appeal that decision.

AFK Sistema called the charges "totally unfounded" and pledged to fight them.

A Rosneft spokesman on September 17 rejected media reports it had held talks to buy Bashneft, an oil producer based in the Bashkortostan region.

Khodorkovsky, however, said he believed Yevtushenkov was paying the price for resisting efforts to take control of Bashneft.

"He did not want to hand over his property under the conditions that were apparently proposed," Khodorkovsky said.

Since AFK Sistema became majority shareholder in 2009, Bashneft has shown one of the highest production growth rates among Russian oil companies.

The holding company AFK Sistema also includes MTS, Russia's largest mobile phone operator, among some 200 other assets.